Re: [Gnu-arch-users] extended attributes

[Tom Lord]

    > From: Chris Mason <address@hidden>

    > I agree EAs are the right way to support acls in general, which
    > is why we went that way for the reiserfs code.

This is an implementation detail.   There is nothing in the semantics
ACLs that implies EAs, and plenty that suggests the possibility of
other approaches to implementation.


    > The real question once you talk about supporting them in arch is how do
    > you store them in the changeset.  


"them" meaning EAs?

or "them" meaning ACLs?

EAs are intractable, for reasons you go on to state.

ACLs are doable but problematic.  It'd help if we had a global
namespace for user ids (but, of course, we don't actually want one for
independent reasons (reasons of independence, in fact)).  Before
getting to representation -- which is a fairly trivial matter --
there's the question of semantics.


    > ACLs are easy because they are just like a change in permission
    > bits (replacement without diffing).  


I was thinking that set membership diffs (diff == both set
differences; patch == adding those back) might be right.  Perhaps not.


    > Generic eas are harder because you can have text files with
    > binary eas etc, so a simple diff won't work.

    > If diff and patch support the EAs, you get 90% of the work done
    > for free.  Functions to copy files around still need tweaking,
    > but that should be minor.

Bleh.

-t